Pressure variable resistance



A. CHURCHWARD.

PRESSURE VARIABLE RESISTANCE.

I APPLICATION FILED JUNE 24. 1919.

1,413,390. 7 ented pr-18,1922.

2,8HEETS-SHEET1.

' if 7 M w A. CHURCHWARD.

PRESSUREVARIABLE RESISTANCE.

APPLICATION FILED JUNE 24,1919.

Patented Apr. 18, 1922.v

2 SHEETSSHEET 2.

DDDD DDDD DDDD DDD DDD DDDD DDDD DDDD L IQI RI TH DDDD DDD DDDD D D D D D D D D J D DD D D D D D b D D D D D DD D DD D D DD D D DI-D 'LD DDD UNITED STATES PATENT OFFICE.

ALEXANDER CHURCHWARD, OF NEW YORK, N. Y., ASSIGNOR TO WILSON WELDER 8t METALS COMPANY, INC., A CORPORATION OF NEW YORK.

PRESSURE VARIABLE RESISTANCE.

Application filed June 24,

To all whom it may concern:

Be it known that I, ALEXANDERCHURGH- WARD, a citizen of the United States, residing at New York city, county of New York, and State of New York, have invented certain new and useful Improvements in Pressure Variable Resistance, of which the following I is a specification.

This invention is an improvement in that type of pressure-variable resistance consisting in a pile of resistance plates, such as carbon, arranged to be variably compressed together and to conduct the current from plate to plate through the contacts between them. The object of the invention is to effect better cooling of the resistance pile. The invention is well adapted to employment as the controlling resistance in an electrical arc-welding system.

One adaptation of the invention is illustrated in the accompanying drawings, in which:

Figure 1 is an elevation of an arc-Welding system including the invention;

Figure 2 is an elevation of the resistance pile proper, embodying the invention;

Figure 3 is a sectional elevation of the pile taken on the plane 3, 3 of Figures 2 and 4;

Figure 4 is a plan view of a portion of the pile; and

Figure 5 is a perspective view of one of the carbon plates of the pile.

The carbon plates 6 are vertically grooved on one side to form air channels between the adjacent plates of the 'pile, and each plate is provided with circular notches 7 in its up-' per and lower edges. The distance between the upper notches is the same as the distance between the lower notches, and the upper and lower notches are vertically opposite to each other, but one vertical edge 8 of the plate extends beyond its adjacent notches considerably further than the opposite vertical edge 9 extends beyond its adjacent notches. Consequently, notwithstanding the pla es are all identical in form and size, if they are stacked together and alternately inverted with their-notches in alignment, each set of plates will project laterally on one side of the pile, as at 8 in Figure 4, so as to leave cooling channels between them','as at 9 in Figure 4. This arrangement greatly increases the cooling surface presented at the Specification of Letters Patent. Patented Apr. 18, 1922.

1919. Serial No. 306,372.

sides of the pile, and provides the said channels for circulation of cooling air between the vertical margins of the alternate plates.

The relationship of alternate pile plates thus accomplished, is maintained by mounting the pile on two insulating rods 10 which enter the circular notches and are held in suitable brackets 11 and 12 mounted on a back board 13. The plates are also further secured by. insulating side rods 14 and 15, extending between these brackets.

Two extra-thick carbon plates 16 and 17 may be included at the ends of the pile, and metal thrust-plates 18 and 19 may bear upon these end plates to transmit the compression to the pile. The rear thrust-plate 18 bears upon an adjustable abutment screw 20 passing through the bracket 11, and the front thrust-plate 19 receives the pressure of the thrust-pin 21 forced inward by the upward moment of the controlling lever 22 pivoted in the bracket 12.

In the illustrated instance the controlling lever receives its pile-compressing moment from a tension spring 23 connected to its outer end, and this'lever moment is varied and controlled by the opposing pull of a solenoid 24 included in the Welding circuit in series with the pile'6, welding electrodes 25 and current source 26, all in accordance with principles now known to the art.

The invention may of course be applied in diflerent specific constructions within the spirit and intended scope of the following claims.

I claim:

1. A variable-resistance pile comprising plates of identic form and material and each having one or more edge notches disposed asymmetrically with respect to one axis of the plate, said plates being stacked in alternately reversed) series with their notches aligned so as to project the edges of each alternate series beyond the edges of the other alternate series.

2. A variable-resistance pile comprising plates of identic form and material and each having one or more edge notches disposed asymmetrically With respect to one axis of the plate, said plates bein stacked in alternately reversed series with their notches aligned so as to project the edges of each alternate series beyond the edges of the other alternate series; and a registering guideem' tering said aligned notches to maintain said relationship of the plates.

3. A variable-resistance pile comprising plates of identic form and material and each having one or more notches in opposite edges disposed asymmetrically with respect to one axis of the plate and'a'symmetrically with respect to another axis of the plate, said plates being stacked in alternately reversed series with their notches aligned on one side of the pile so as to project the edges of each alternate series beyond the edges of the other alternate series. r

at. A variableresistance pile comprising plates of identic form and material and each having one or more notches in opposite edges disposed asymmetrically with respect to one axis of the plate and'asymmctrically with respect to another axis of the plate, said plates being stacked in alternately reversed series with their notches aligned on one side of the pile sova s to project the edges of each alternate series beyond the edges of theother alternate series; and a registering guide entering said aligned notches to maintain said relationship of-the plates.'

5. A variable-resistance pile comprising A plates of identic form'and material and each ALEXANDER GHURCHWARD. 

